Patent · US Expired

Catalyst for purifying exhaust gases and process for producing the same

US5702675A · kind A · utility

24Cited by
8References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 13, 1995
Grant dateDec 30, 1997
Priority date
Expiry dateDec 13, 2015

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02T10/12
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A catalyst for purifying exhaust gases, which is composed of a catalyst substrate, a first porous support layer supporting barium as a NOx-occluding material and palladium, which is formed on the catalyst support, and a second porous support layer supporting platinum, which is formed on the first porous support layer. Platinum efficiently oxidizes nitrogen monoxide to be converted into nitrogen dioxide. Palladium is supported in a highly dispersed state even after endurance to act as inlet and outlet of barium for nitrogen dioxide or the like, whereby absorption and emission of nitrogen oxides can be performed smoothly, and accordingly, the purification performance for nitrogen oxides is improved.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.